Tap some more.

She's going in." Much puzzled by the queer noises, for no one had ever before put a tic-tac on her window, Mrs.Mooney went back to her dining-room.
But she could not read.
"I must find out what that is," she said to herself.

"If it's burglars, I'm going to call for help.

Suppose it should be thieves trying to cut one of the window-panes?
I've read of such doings." Now, the widow was less afraid of something bodily, like burglars, than she was of "spirits," so she resolved the next time she heard the queer tapping to run out and call for help.
In a little while Bob pulled the string again, and the dangling nail went tap! tap! tap! against the pane.
"Here she comes!" exclaimed Ted in a whisper as the door opened.
And this time, instead of contenting herself by merely looking about, Mrs.

Mooney came out on the porch.